Researchers at the Washington State University have found that organic farming methods can help reduce the amount of nitrogen draining into ground water, which is harmful to the environment and poses a potential health risk.

Conventional farming practices apply synthetic fertilizers, which are the primary source of nitrogen pollution in water systems and the atmosphere. As nitrogen leaches from the farm, ground water transports the nutrient into the surrounding water system.

The excess nutrients produce a dense growth of algae and other organisms that reduce oxygen levels in the water, choking out other plants and animals. Nitrogen from farms is also a potential health risk if it leaches into domestic wells.

Dr. John Reganold at the Washington State University and colleagues at Stanford University and The Land Institute examined the use of organic fertilizers on nitrate leaching, or draining, in soils.

With funding from the U.S. Department of Agriculture’s Cooperative State Research, Education and Extension Service, the researchers examined nitrate leaching in an apple orchard under three management systems: organic, conventional and integrated.

During the yearlong experiment, organically grown trees were fed either composted chicken manure or alfalfa meal, while conventionally raised trees were given calcium nitrate, a synthetic fertilizer widely used by commercial apple growers.

Trees raised using the integrated system were given a blend of equal parts chicken manure and calcium nitrate. All trees were given the same amount of nitrogen, no matter what the source.

The study found that annual nitrate leaching was four to five times higher in the conventional treatment than in the two organic treatments, with the integrated treatment in between.

The organic sector is the fastest-growing sector in the agricultural economy. Washington State University is pioneering the effort to train future generations about organic agriculture. The new organic agriculture systems major is the first of its kind in the country and plans to meet the growing demand for experts in organic farming.

The organic agriculture program at WSU prepares not only aspiring growers of organic food, but also students who are interested in related industries, such as direct or global marketing, food quality, pest management or animal science.